Sea kelp is a type of edible seaweed that is packed full of nutrients that benefit your health. Sea kelp contains vitamins, minerals, and antioxidants. Taking sea kelp supplements has been linked to weight loss, boosting your cardiovascular health, and improving digestion. The high level of iodine in kelp means that it can also help address thyroid disorders.

Sea kelp has been used in Asian cooking for centuries. Recently, using powdered sea kelp or sea kelp supplements has become popular because of its many health benefits. However, there are a few precautions that you need to take if using kelp products for medicinal purposes.

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In this article, I will look at what scientific research has revealed as to the many benefits of sea kelp.

What is Sea Kelp?

Sea kelp is a type of large brown algae that grows in nutrient-rich seawater around the coasts of many countries. Kelp belongs to the Laminaria species and is also called brown seaweed or kombu in Japan and China. (1)

Kelp is boiled and then dried before being turned into a powder. Kelp is sometimes used as a thickener for soups, jellies or ice cream. From all types of seaweed, sea kelp has the highest content of iodine. (1)

In Asian cuisine, kelp is a delicious food that is enjoyed almost daily by many people.

Kelp Nutrition

Many of the kelp health benefits are due to its rich content of vitamins, minerals, and trace elements.

The United States Department of Agriculture (USDA) reports that 10 grams of kelp contain the following nutrients: (2)

4 calories

17 mg calcium

9 mg potassium

3 mg iron

18 mcg folate

Kelp also contains trace amounts of vitamins A, C, and K.

One of the reasons that many people take kelp pills is for its iodine content. The journal Thyroid Research reported that the average content of iodine in dried kelp is 1,542 mcg/g. (1) The National Institutes of Health says that the recommended daily intake (RDA) of iodine is 90–150 mcg in children and adults and 220 mcg in pregnant women. (3)

Studies show that the bioavailability of iodine from seaweeds is very high. This means that a high percentage of the iodine is absorbed by the body. (4)

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Many of the sea kelp benefits come from its high levels of antioxidants. Research published in the journal Marine Drugs found that brown seaweeds such as kelp contain a group of compounds named fucoidan. These compounds have an antioxidant effect with anticancer properties. (5)

Benefits of Sea Kelp

Let’s look in more detail at how kelp extracts may benefit your health.

Kelp for Weight Loss

Taking seaweed tablets or kelp pills may help you lose weight.

One of the reasons that scientists say kelp promotes weight loss is because it contains alginates and fucoidans. These seaweed compounds have anti-obesity properties because they inhibit lipid absorption and increase feelings of fullness. For example, researchers noted that brown seaweed powder mixed in a beverage helped to suppress food intake. (6)

Sea kelp tablets can promote natural weight loss because antioxidant substances in seaweed help to reduce body weight. Research has found that fucoxanthin found in kelp helps prevent body fat accumulation. (7)

Researchers from England discovered that dietary fiber in sea kelp can help fight obesity. In one trial, taking kelp extracts helped fat to pass through the body quicker without being absorbed. The scientists said that alginates from sea kelp help to “significantly reduce fat digestion.” (9)

The journal Nutrition Reviews reported that seaweeds contain proteins and antioxidants that aren’t found in other types of food sources. Many of these compounds can help to improve gut health and reduce obesity. (10)

Of course, using kelp for weight loss isn’t a miracle pill in itself, but you can combine it with other measurements to lose weight, such as these 12 simple tweaks for weight loss.

Sea Kelp Contains Iodine and Can Help Regulate Thyroid Levels

Kelp is a rich source of iodine and can help to treat various thyroid disorders.

Another trial found that taking powdered kelp supplements can help treat hypothyroidism. People with an underactive thyroid took 1-2 g kelp powder a day. This contained 200-400 µg iodine. Researchers noted that the kelp supplementation helped to normalize thyroid function and treat hypothyroidism that is due to an iodine deficiency. (12)

Sea Kelp Can Help Prevent Blood Clotting

Compounds in kelp have anticoagulating properties that can lower risks associated with blood clotting.

The journal Thrombosis Research found that compounds called fucoidans in brown algae (kelp) help reduce blood clotting. Scientists found that kelp extract supplements prevented thrombosis in rats. They concluded that extracts containing fucoidan from brown algae have the potential to be an antithrombotic oral supplement. (13)

Other studies have suggested that kelp extracts could be a natural alternative to heparin to prevent blood clotting. Heparin is a popular drug to prevent deep vein thrombosis. (14)

Sea Kelp Can Help Keep Your Heart Healthy

Extracts from sea kelp also benefit your heart because they have antioxidant and anti-inflammatory properties.

A review of around 580 studies found that polysaccharides from brown seaweeds have a beneficial effect on the cardiovascular system. Kelp extracts help to lower blood pressure, prevent clotting, and reduce inflammation. These effects can help prevent cardiovascular disease. (15)

Sea Kelp Has Properties That Can Lower Cholesterol

Kelp extract benefits your heart because they also help lower cholesterol levels in your blood.

Researchers have found that brown kelp contains fucosterols that help to lower plasma cholesterol levels. (18) A review of the effects of algae extracts also found that kelp extracts have blood cholesterol reducing properties. (19)

Sea Kelp May Lower Blood Glucose Levels

Marine foods like kelp can also help to control blood glucose levels and lower fasting blood glucose.

Scientific research has revealed that consuming seaweed supplements can help diabetics control their symptoms. One study involved taking 48 g of seaweed extracts for 4 weeks. After the 4 weeks, researchers noted the blood glucose levels after a meal were lower, as well as fasting blood glucose levels. The seaweed supplements also lowered blood lipids (a type of fat in blood) and increased antioxidant levels in the blood. (20)

Sea Kelp Can Improve Digestive Health

Taking kelp dietary supplements can also help improve your digestion because they act as a prebiotic.

Research carried out in 2018 found that brown kelp supplements help beneficial gut bacteria to flourish. Kelp contains dietary fiber that has prebiotic properties. This helps to “feed” good bacteria that are essential to your digestive health. Taking kelp supplements increase gut bacteria strains such as Lactobacillus, Bifidobacterium, and Enterococcus. (24)

Sea Kelp Can Increase Bone Density and Prevent Osteoporosis

One of the many benefits of supplementing your diet with kelp extracts is to improve bone health.

Osteoporosis often affects women over their 40s and can lead to brittle bones, bone fractures, and back pain.

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Research has discovered that extracts from sea algae help suppress osteoclasts which are responsible for poor bone structure. Scientists were able to identify specific compounds in kelp extracts that help to strengthen bones and have an anti-osteoporosis effect. They concluded that marine algae can be used as a medicinal food that can help prevent osteoporosis. (25)

Another study found that an algae supplements enriched with calcium were superior to calcium carbonate or calcium citrate. These are common supplements to help prevent the effects of osteoporosis. (26)

Sea Kelp Has Anticancer Properties

The antioxidant properties of sea kelp may have a beneficial effect in helping to treat and prevent various types of cancer.

The International Journal of Biological Macromolecules reported in 2013 that compounds in sea algae extract have anticancer potential. For example, polysaccharides have antioxidant effects that can have therapeutic potential in cancer treatment. (27)

A comparative study of the medicinal properties of various types of brown seaweeds found that they could help prevent the growth of certain tumors. (28)

Other research has found that the compound fucoxanthin that is naturally present in kelp can destroy cancerous cells. The seaweed extracts showed potential in treating leukemia, prostate cancer, gastric cancer, and bladder cancer. (30)

Studies from Japan indicate that consuming seaweed daily could also have a protective effect against breast cancer in women. (31)

Of course, more research has to be done on how kelp extracts benefit cancer treatments. However, research does show that kelp has anticancer potential.

Sea Kelp Cosmetic Products Can Boost Skin Health

The high levels of antioxidants and anti-inflammatory effect in sea kelp mean that kelp extracts are excellent in cosmetic products.

A review of many studies into the benefits of kelp extracts on your skin found that brown algae have a number of dermatological uses. Creams and topical applications containing algae extract can help treat eczema, skin infections, and protect the skin from cellular damage. (32)

Precautions and Side Effects

Although kelp dietary supplements have many benefits for your health, there are a few precautions you should be aware of.

Effect on thyroid function

Kelp powder benefits thyroid function if an iodine deficiency results in hypothyroidism. However, taking too much sea kelp could result in an iodine overdose.

Regarding the safe use of kelp supplements, scientists say that it’s important to pay attention to their iodine content. For example, some kelp supplements contain 225 mcg iodine which is 150% of the recommended daily intake. (33)

Arsenic content

High dosage of kelp supplements could also lead to arsenic poisoning. Researchers have found that kelp extracts can contain levels of arsenic.

However, kelp contains inorganic arsenic which is judged to be less-toxic than organic arsenic. According to the European Pharmacopoeia Commission, up to 90 ppm arsenic in kelp is allowable in medicinal products. (33)

Heavy metal content

Because kelp absorbs minerals and nutrients from the sea, it can also absorb heavy metals if it grows in polluted waters.

A study of 426 samples of seaweed sold in one Asian country found traces of lead, arsenic, mercury, and cadmium. However, researchers said that there is a low probability of toxicity from seaweed consumption if taken in the recommended dosages. (35)

The Best Kelp Supplements

As kelp can absorb heavy metals, you should look for kelp supplements that are purified. Also, look for high-quality seaweed supplements that are from clean waters.

You can also buy in health stores and online stores organic kelp tablets or powder that is free from toxic substances.

How to Consume Kelp

You can consume raw, cooked or dried kelp. If you consume fresh kelp, make sure to rinse it well. Apart from taking kelp supplements, you can add kelp powder or flakes to your food.

For example, you could add dried kelp powder to soups, on salads, or in your favorite smoothies.

You can buy kelp flakes or dried kelp online or in Asian stores and sprinkle on your food to season it.

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